Also known as variously “Russian bassoon”, "serpent droit" and “serpent anglais”, the bass-horn appeared first in England at the end of the 18th century. With its conical bore and cup-shaped mouthpiece, it is in fact a serpent with a bassoon-like body, a brass crook, and a lip-vibrated mouthpiece. After 1815 the bass-horn became popular on the Continent and was a regular member of military bands throughout Europe until about 1830.

The brass ferrule at the top of the body is inscribed: FRATELLI GARIGNANI MILANO. The body of the instrument is of maple. The joints are covered with brass ferrules. The crook and mouthpiece are of brass, and the bell in the form of a serpent's head is of painted metal. There are six finger holes and one thumb hole in addition to three holes that are covered by keys. Overall length 113.5 cm.